There are many instances where thickened cleaning compositions are useful. For example, on vertical surfaces, it is useful to have a thickened composition to maintain the composition on the surface for a sufficient length of time to accomplish its purpose. In addition, thickened caustic compositions of this type are known to be useful for cleaning and opening clogged household drains.
Typically, a combination of fatty substances, protein or cellulose fibers contribute to clogs in household drain pipes. Many commercially available liquid compositions are sold to open these clogged drain pipes. Thickened aqueous hypochlorite bleaches are amongst the various compositions known for this purpose.
One of the early compositions of this type is disclosed in U.S. Pat. No. 4,388,204. This patent discloses the use of a ternary thickener system containing an alkali metal salt of an N-alkyl, N-fatty acyl amino acid such as sodium lauroyl sarcosinate, an alkali metal salt of an alkyl sulfate and an alkali metal sulfate salt of an aliphatic ethoxylated alcohol. However, these compositions are disadvantageous primarily because they dissolve so rapidly. Therefore, they fail to reach the clog in the drain in many instances, before being severely diluted.
In U.S. Pat. No. 5,055,219 there is described a drain opening composition that is said to be improved over compositions such as described in '204 in that the composition contains a system of a quaternary ammonium compound (quat) and an organic counterion that provides for a composition has special viscoelastic properties. The composition, when poured into a clogged drain does reach the clog but coming out of the container, the composition has low viscosity and is difficult for consumers to pour easily. Splashing and delivery of more composition than desired is common. Related patents include U.S. Pat. Nos. 4,900,467 and 5,011,538.
The disclosure of the '219 patent is interesting however, since comparative examples show the unsuitability of compositions having sarcosinates alone as the thickening agent (table V). Another comparative example shows the use of myristyl/cetyl dimethyl amine oxide in the absence of the quat. Very low viscosity compositions are reported. Suitable compositions are obtained only with the quat in combination with the myristyl/cetyl dimethyl amine oxide.
Other references show the use of amine oxides in hypochlorite bleaching and cleaning compositions but these are branched chain amine oxides. We have found that the use of branched chain amine oxides does not give the properties desirable for drain opening compositions. (See U.S. Pat. No. 4,229,313)
Thus, there is a continuing need for thickened cleaning compositions, particularly those that are capable of cleaning out clogged drains. The composition desirably should be capable of going through standing water without substantial dilution.